They wear the anxious smile you get when you’re dragged to a party where you don’t know anybody. You might have fun, or end up hiding in a corner talking to a houseplant.

Or in this case, stepping on a stranger’s toes.

But they’ve heard they’re in for a good time, so they bravely link arms with their partners, then wait for the bandana-wearing guy with a microphone to call out their next moves.

“Gentlemen, lead that lady on the right, take six steps,” dance caller Dean Snipes commands as they spread out into two big lines across an old gym floor. “Swing your neighbor, swing …

“Look for a new neighbor up and down the hall and swing.”

And off they go.

This is contra dancing, which staked roots on farms in 17th-century England and France, then resurfaced in America’s 20th-century folk-music scene. Today it thrives among long-time loyalists and a new generation that’s discovered it at music festivals, on college campuses and even Facebook, Twitter and Instagram.

From artsy Asheville to Atlanta, New England and California, to this former elementary school in Charlotte’s Chantilly neighborhood, communities of contra dancers gather weekly for what feels like an old-fashioned barn dance.

It’s part line dance, part square dance and involves lots of swinging, stomping and switching partners. And social graces such as smiling, looking your partner in the eye and helping beginners through awkward moments.

As the band plays its fiddles, keyboard and guitars, dancers divide into two lines, facing their partners. Two couples form squares, dance together, switch partners, then move down the line to the next couple. By the end of the night, they’ve danced with just about everyone.

Because it is close to the Elizabeth and Plaza-Midwood neighborhoods’ booming bar and music scenes, it’s no surprise to see the young and trendy, with their piercings and brightly dyed hair. They blend into a colorful collage of generations and dress codes.

Picture a dapper 78-year-old man in wingtips twirling a little girl in a fancy dress while his wife dances with a 20-something guy in a black T-shirt and skinny jeans. Or a college girl in a vintage velvet dress patiently partnered with an earnest 11-year-old boy in khaki shorts and a button-down shirt.

“It’s very egalitarian,” says George Bame, a retired network engineer. “I’ve danced with people for years and I didn’t know anything but their first names. I didn’t know if they were a neurosurgeon or a janitor.

“It’s a real social event, but it’s not threatening. It’s not a meat market.”

Many welcome this friendly, clean-living alternative to the bar scene. There’s no alcohol or bad behavior allowed. Make inappropriate advances on someone, and you’ll be asked to leave.

Singles and couples are all welcome and the group has both in abundance. But singles be warned: There’s a running list of people who met here or at other contra dances and now come as couples. One of those couples now brings a baby who dances with them.

“Sometimes we have boy meets girl, sometimes we have marriages come out of it,” said Snipes, the caller who started contra dancing 21 years ago when friends gave him two choices – he could go to a dance with them or stay at their weekend campsite alone.

Reluctant then, leader now.

From gym to dance hall

The local group traces its history to Nancy Howe, who started the Charlotte Country Dancers in 1973 and was its lively leader for decades. At the turn of this century, attendance dwindled as dancers aged or moved.

Then in 2007 the group, also known as The Charlotte Dance Gypsies, leased Chantilly Hall as its headquarters. In other incarnations the building was a Catholic elementary school, and later, a public school for students with behavioral problems.

Many volunteers, including Howe, Snipes, Gretchen Caldwell and Sandy Brand, set about turning the former gym into a dance hall.

They rescued an old floor from a dance group in Charleston, where it had been stored in a garage. They hauled it to Charlotte, laid it down and refinished it.

Love blooms on dance floor

Along the way, Snipes, then a bachelor, and Brand, a widow and retired science teacher, got to know each other quite well.

“I think we would make a good couple,” he said to her one day.

“A couple of what?” she thought.

“We finished the floor with three layers of polyurethane, and by that time we were dating,” Snipes said.

Seven years later, they’re still together.

The new building brought a new generation.

Attendance has increased steadily, from under 40 at its low point, to about 75 to 120 people showing up regularly for Monday night dances, Brand said.

“You either get hooked or you think you’ll never get past the dizziness and you don’t come back,” she said.

The music is live, performed by rotating bands from Charlotte, Asheville, the Triangle area and Greenville, S.C. They play a variety that includes New England, Celtic, Canadian and Old Time music. Touring bands from across the United States and Canada visit for special dances on occasional Wednesdays and Saturdays.

The group also hosts a monthly Saturday night potluck dinner and dance.

And hundreds of people from across the country show up for an annual contra-dance weekend each March at Camp Thunderbird.

Many come to the weekly dances with friends and then invite other friends. Some young adults return with their parents, and some parents bring children, young or already out on their own.

While the love stories are legendary, the place is also filled with people who started contra dancing to lose weight or gain confidence or master a new skill.

‘Part of a community’

Indian Trail resident Rachel Carroll, 18, is a regular among the younger set. She discovered contra dancing at an arts festival in Asheville several years ago, then found the Charlotte group.

“I come as often as I can,” she said. “My little sister is here and so is my 7-year-old brother.”

Safe is how Rachel and others describe the dances.

The “gentlemen” are expected to act as such. And the “ladies” appreciate that. You don’t have to be male to play the gentleman’s role, or female to be the lady. If women outnumber the guys, or vice verse, you dance with whoever is available.

“It’s taught me how to be part of a community,” said Rachel Carroll, a freshman at the University of Southern California who treasures the friends and mentors she’s met on the dance floor.

“To give you an idea of how much I love it, when I leave for school, this is going to be one of the hardest things to say goodbye to.”

She’s hopeful, though: A friend told her about a great contra-dance community in Pasadena.